1. Field of the Invention
This invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate. Examples of substrates to be processed include semiconductor wafers, substrates for liquid crystal displays, substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells.
2. Description of Related Art
In a production process for a semiconductor device or a liquid crystal display, a substrate, such as a semiconductor wafer or a glass substrate for a liquid crystal display, is processed, for example, one by one. Specifically, a chemical solution is supplied to the substrate and a surface of the substrate is processed by the chemical solution. Thereafter, pure water is supplied and the chemical solution adhering to the substrate is rinsed off. After the chemical solution has been rinsed off, IPA (isopropyl alcohol), which is lower in boiling point than water, is supplied to the substrate and the pure water adhering to the substrate is replaced by IPA. Thereafter, the substrate is rotated at high speed to remove the IPA adhering to the substrate from the substrate and the substrate is thereby dried.
However, with such a substrate processing method, a pattern formed on the surface of the substrate may collapse during drying of the substrate. U.S. Patent Application Publication No. 2010/0240219 A1 thus discloses a method in which drying is performed after hydrophobizing the surface of the substrate to prevent pattern collapse. Specifically, a hydrophobizing agent is supplied to the substrate to hydrophobize the surface of the substrate. Thereafter, IPA is supplied to the substrate and the hydrophobizing agent adhering to the substrate is replaced by IPA. After replacement of the hydrophobizing agent by IPA, pure water is supplied to the substrate and the IPA adhering to the substrate is replaced by pure water. Thereafter, the substrate is rotated at high speed to dry the substrate.